A senior U.S. diplomat said Tuesday that China’s objections to deployment of a controversial U.S. missile defense system in South Korea were “unwarranted,” and he urged China to redirect its response to “a better use.” The United States has deployed the first elements of its Terminal High Altitude Area Defense (THAAD) missile defense system in South Korea, following North Korea’s launch of at least four ballistic missiles Monday. Beijing strongly opposed deployment of the advanced U.S. weapons system as an unnecessary and provocative military escalation, and it said the powerful radar the system uses to track incoming missiles also posed a potential threat to China. State media called for a boycott of South Korean goods and sanctions after the Korean conglomerate Lotte Group approved a land swap that paved the way for the THAAD deployment. “We think China’s objections, if in fact they are based on China’s security concerns, …